The use of lead solder and brass fittings has only been illegal in the uk since 1999, and these are still legal to use in central heating systems. This leads to people having access to these fittings and products, and them being used illegally.
"WaterSafe Warning after Kitchen Fitter Fined for Illegal Use of Lead Solder on Water Pipes" https://www.watersafe.org.uk/news/latest_news/watersafe_warning_af/
Unfortunately this problem is sort of universal and I imagine if I google other countries I will find similar.